273 Build....Numbers Help !

[pastortom1]

Guys.......

The shop just punched my 1967 273 2 Barrel to 30 over, and shaved 10 thousandths off the heads.........

Can someone please tell me:

1. What is the correct number for displacement now?

2. What would be the correct compression ratio?

 

[fishy68]

Since I don't know the stock bore diameter I don't know exactly how many cubes it'll add but I'd guess 5 more cubes.

There are so many variables when it comes to the compression ratio I'd need a bunch more info to figure it up. Need head combustion chamber CC's, type of piston such as flat top with or without valve reliefs and if it has reliefs how many CC's are they, or dish piston and how many CC's the dish is, pop up and if so how many CC's it is including the valve relief CC's. Also need how far the piston sits down in the hole or if it's above deck how far above is it. Need the head gasket bore and thickness (compressed). Get me all that and I can figure it up.

 

[djwhog]

I recall a .040 over is about 280, so you should be at around a 278 5 sound about right.

Volume formula
Formula for volume of a cylinder, V =(Pi)(h)(r)(r)

So it is pie x height (stroke) x radius squared ( half bore diameter squared)


You had stock 9.0 pistons?

Then about 9.4

 

[2 Darts]

I get 278.59 for CID.

In the same boat with Fishy68 on comp ratio. Too many variables.